Improvement in loose pulley



UNITED STATES PATENT QEEIcE.

DAVID HARRINGTON, OF VOROESTER, ASSIGNOR TO HIMSELF AND S. A.

' WOODS, OF BOSTON, MASSACHUSETTS.

I IMPROVEMENT IN LOOSE PULLEY.

Specification forming part of Letters Patent No. 50,911S, dated Augustll, 1868.

To all whom it may concern:

Beit known that I, DAVID HARRINGTON,

of WVorcester, in the county of \Vorcester andw State of Massachusetts,have invented an Improved Loose Pulley 5 and I do hereby declare thatthe following, taken in connection with the drawings which accompany andform part of this specification, is a description of my inventionsufficient to enable those skilled in the art to practice it.

My invention relates to the construction of loose pulleys with referenceto provision for self-lubrication of the hub or bearing-surface thereof,and my improvements have particular reference to that class of loosepulleys in which a bushing is inserted.

My invention consists, primarily, in combining, with an oil-chamber madearound the bushing, oil-passages leading through the bushing, and madenarrow at the bearing-surface and flaring back to the chamber, theseoil-passages being filled with wicking or other fibrous material, which,keeping saturated with oil, aords a continuous supply of lubricant tothe shaft or journal, the oil-chamber and oil-passages being soconstructed that the journal is kept free from excess of oil bycentrifugal action when theV wheel Y is rotating,

while-at whatever point it stops some one or more of the oil-passageswill be in position to cause the oil to be carried by capillaryattraction to the shaft.

The drawing represents a loose pulley embodying my improvements.

A shows a central cross-section on the line a@ B shows a section on theline z z. C shows an outside view of the bushing.

a denotes the pulley, provided with a bushing, b, the bushing being fastin the hub, but there being formed in the hub and extending around thebushing a chamber, o, for holding the lubricant. Extending through thisbushing, from the oil-chamber to the inner surface of the bushing, areoil-passages d e j', which may be long and parallel with the axis of thepulley, as seen at d, or diagonal, as seen at c, or maybe round, asshown at j'. But, however arranged in these respects, each passage ismade small or narrow where it opens into the bearing-surface ofthe hub,but enlarges or ares back to the oil-chamber, as seen in the drawings,so that, though each passage opens freely for passage of oil from thechamber, it is sufficiently contracted to pervent too ready flow of thelubricant to the shaft. These passages, however, are -to be filled withwicking or other fibrous material, through which the oil penetrates, orby which the oil is taken up by capillary attraction and conveyed to thebearing-surface of the hub.

The outer surface of the oil-chamber c is made 11a-ring, or enlargesfrom the ends of the chamber toward the center, as seen at A, so thatwhen the pulley is in rotation the oil, under centrifugal action, isthrown toward the center of the chamber-that is to say, to the partsofthe chamber most remote from the axis of the pulley-and is thus keptfrom being thrown beyond the ends of the pulley. To still further retainthe lubricant at or toward the center of the chamber, I stretch bridgesg across the chamber, as seen at A and B, mal; ing openings h throughthem to allow the passage of the oil to the center, these bridges alsoserving as supports to the bushing. While the rotation of the pulleythus causes the excess of oil to bey thrown to the center of thechamber, whenever the pulley stops the lubricant iiows through theoil-passages which are lowermost, and is distributed along the lowerside of the shaft, so that the whole surface is lubricated when thepulley again starts. To prevent the oil from going beyond the hub on theshaft, a leather ring or collar, t', may be drawn over the shaft, theouter edge of this rin g projecting into the chamber c, so that the oil,by centrifugal force, will be reconducted back into the chamber,'thc endopening h of the pulley being larger in diameter than the shaft. At oneend of the pulley the hub is shown as closing down upon the bushing toconiine the oil within the chamber, and both ends may be closed in thisway, or both may be open, and a leather collar, z', may be placed uponthe shaft at each end, or at only one end.

By this construct-ion the shaft and hub are kept well and constantlylubricated with a small quantity of oil, and wit-hout liability of theoil ruiming endwise beyond the hub.

I claim- 1. In combination with the bushing b (and oil-passages leadingthrough it) and the surrounding oil-chamber c, the enlargement of l 4. Ialso claim the collar vl, placed upon the such chamber from its endstoward its center, shaft and leading into chamber c, substausubstantially as and for the purpose set forth. tizilly as shown anddescribed.

2. I- also claim7 in combination With the enlarging chamber c, thebridges g, for keeping DAVID HARRINGTON. the loil toward the centerofthe chamber, substantially as shown and described. Vitnesses: A

3. I also claim the flaring oil-passages d e f, E. B. STODDARD,substantially as shown und described. H. lV. VHEELER.

